Reading defeated me when I was obligated to hold-to a particular book until finished. A foray becomes a commitment becomes an obligation becomes a tedium becomes an avoidance becomes no reading at all.
That was true in a corollary way with books loved: life transforms itself so much with a good book that the next book -- even if equally as good (!), but of a different author and different style -- suffers by letting the built enthusiasm of 'Book One' lapse.
So, I read in stacks, never going too far into one book before arbitrarily putting it down and opening another.
The 'three cycles' have developed from there:
1) Group One: the bedroom stack, often seven books, usually no more than ten, serves to greet me before sleep, an hour or two, if I can afford the time, or 10 minutes, 2 pages, if not. These are books that can be read in a period of months, possibly weeks, short or very engaging so as not to remain in the stack too long, not overstay a welcome. One or two of these also serve as 'travel' books to take to appointments where waiting in line or to take on trips.
2) Group Two: the day stack, two or three that are long and that find a rhythm to fit comfortably a period clearly more than a year or two. The enthusiasm level may be high, and these books are greeted as dearly as those in Group One, but their periodicity is longer, and the 'rotational mismatch' with those in the first group deserves separate reading attention -- weekends, vacation times, return visits.
3) Group Three: the auxilliary stack, maybe another 6 to 12, those that can't be handled easily before sleep: print too small, chapters too long and not accommodatingly paced, dense style (descriptive, too technical, 'educative'), but containing material that wants to be read and has personal virtue. These may have started out as Group One, but quickly got identified as something else. Too important and well-chosen simply to give away, they serve as 'change-ups' for the other two groups, and never (re-)enter routine consideration for regular reading rhythm, only periodic sampling for reassessment of virtue.